Apparatus for obtaining salts from salt-bearing ores.



P. G. DARLING. APPARATUS FOR OBTAlNlNG SALTS FROM SALT BEARING oRES APPUCATION FILED JULY Il, l9l4.

5 nu? Wto/z LW a SHEETSAHEEI l.

LMA/LW htented @at 2E), 1

(y 351,37( S @Mom/w P. G. DARLING. APPARATUS FOR OBTAINING SALTS FROM SALT BEARING GRES.

APPLICATION FILED JULY 17, i914. Lywgn, Patented ome. 29, 191s.

8 SHEETS-SHEEI 2K P. G. UARLING. APPARATUS FOR OBTAINNG SALTS FROM SALT BEARING ORES. APPLICATION 1111213 1uLY11.1914.

8 SHEETS-SHEET 3.

Patented A001. 29, 11118.

Wmme@ P. G. DARLING. APPARAUs FOR OBTAINING SALTS FROM SALT BEARING oREs. APPLICATION FILED JULY 17.1914.

Patented Oct. 29, 1918.

8 SHEETS-SHEE14.

|1567 *Sie 5 wu@ n10@ P. e. DARLING.

y APPARATUS FOR OBTAINING SALTS FROM SALT BEARING ORES.

APPLICATION F|LED JULY 17.1914. 'LPQQD Patented @et 29, 1918,

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P. e. DARLING.

.APPARATUS FOR OBTAINING SALTS FROM SALT BEARING ORES. APPLICATION FILED JULY I7. 1914.

L283@99 Patented @en 29, m18.

SHEETS-SHEEI 6.

P. G. DARLING. APPARATUS ron OBTAINING SALTS FROM SALT BEARING GRES. APPLICATION FILED IULY III 19141 l'm@ Patented Im 29, 1918.

8 SHEETS-SHEET 7.

P. G. DARLING. AEPARATUS FOR OBTAINING SALTS FROM SALT BEARING ORES.

APPLICATION FILED JULY 17.1914. lQ-Q. Patented 001.-. 29, 1918.v

8 SHEETS-SHEET 8.

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PHILIPG. DARLNG, OF WILMINGTON, DELAWARE, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO EQI. DU PONT DE NEMOURS AND COMPANY, A CORPORATION OF DELA- wann.

the recovery of salts from salt bearing ores,

but it is to be understood that it hasapplication to tlierecovery of soluble constltuents from any mixture containing soluble as well as insoluble compo-nente. lt is particularly applicable,.however, tothe recovery of sodium nitrate from caliche.

The object of my invention is to provlde an apparatus which has. many advantages over previous apparatus used for the recovery of soluble constituents of the character indicated. The particular advantages of the 'same will appear from a consideration of my apparatus as hereinafter set forth in detail.

While my invention is capable of being carried out in many dierent ways and While many di'erent forms of apparatus may be used for carrying out my invention, for the purpose of illustration, I have Shown only one form of my apparatus in the accompanying drawings, in which,

Figures l and 1a are, together, a s1de elevation, partly in section, of a complete apparatus embodyingmy invention;

Fig. 2 is a front end elevation of Fig. 1, the ore feeder being shown in section;

Fig. 3 is a section of Fig. 1 on the line Fig. 4 is a section of Fig. 1l on 'the line Figs. 5, 5a and 5b together form an en-v larged vertical sectional view of the troughs l and 13 and adjacent parts, some of the parts being shown in elevation;

Fig. 6 is a section on the .line 6-6 of Fig. 5

Fig. 9'7 is a front elevation of Fig. 1; and

Fig. 8 is a sectional view showing the perforated disk arrangement for regulating the feed of the fluid. y

ln the drawings l have shown a main dissolving trough preferably set on masonry Specication of Letters Patent.

APPARATUS FOR OBTAINING SALTS FROM SALT-BEARING DRES.

Patented Oct. 29, 11915..

Application medcruly 17, 1914. serial No. 351,487.

walls so as to form a combustion and heating chamber between the walls and beneath the said trough.. The trough 1 has a screw conveyer 2 therein, which may bep/driven in any desired manner from any suitable source of power. I have, however, shown a worm wheel 2a and a worm 2b for this purpose. The screw Vconveyer has a plurality of apertures 3 passing through the blades of the same, so as to permit the liquids in the trough to flow in an opposite direction to the solids'therei'n. The apertures 3 are located in staggered relation so that the ow ofthe liquid will be momentarily arrested at different points in the trough 1. fThe solid caliche is fed into the trough at a point near the front end of the trough, as shown, from some type of ore feeder, so ineased as to prevent the direct escape of steam from the trough. Mother liquor for dissolving the soluble constituents from the caliche is fed into the trough 1 by means of a pipe`9, which may be located at any point found most desirable, preferably toward the rear end of the trough 1 and preferably in the top of the trough l. The mother liquor isy contained in a tank 9, for instance, and its flow is regulated preferably as by interposi'ng a diaphragm 9b in such pipe, the. said diaphragm being provided with an opening therein calibrated to pass only the desired quantity of liquor. The trough 1is maintained at an elevated temperature, preferably by means of a burner 10 which may bel an oil burner and is located beneath the same and extends into the combustion chamber before mentioned. The products of combustion are carried off by a stack at the rear end of the apparatus as will be later described. r1he solid vmaterials which are undissolved by the mother liquor in the trough l, are conveyed to the end ofthe trough 1 at the right of Fig. 5 until they are discharged therefrom into an inclined trough 13, having a screw conveyer 14:, whose screw 15 is preferably in the form of a `ribbon surrounding but largely spaced away from the shaft. The conveyor 14 may along the trough l13,l until the is set low enough so that the liquor can flow they are 'disthrough end thereof, and in the present instance are shown as being discharged'4 into a car to be taken away. A pipe 17 preferably equipped like the pipe 9, .and supplied from a tankv .water h 13,-

17a is prov1ded for` discharging wash upon theascending'solids in the trou so that the undissolved nitrate an the mother 'liquor carried thereby, which has not drained out, may be washed out of vthe same as far as possible. Pure water may be introduced near the upper 'end of the in-l clined trough through a pipe 18 supplied vfrom a tank 18a.. The liquid feed level from all the tanks may be regulated in any desired manner as by the simple orifice disk and ball cock. .Between the trough 1 and the trough 13, there is located a gate 19, which, in order to prevent the escape of the steam from the trough 1, has its lower end sealed in the body of liquid within the apparatus. A similar gate 19El is located at the other end of trough 1 for the same purpose. The liquid' in the trough 1, aspreviously indicated, asses through the trough 1 in the opposite irection to the movement of the solids therein, and the said liquid containing the dissolved nitrate passes outwardlyfrom the end of the trough 1, over a lip 20, and into a trough 21 out of which it flows through a pipe 22 into a reservoir 23 beneath the inclined trough 13. The reservoir 23 is preferably built between the masonry walls sustaining the trou hs 1 and 13, and such reservoir extends pre erably to the rear end of'the said walls, beneath the trough 13. A pump 24 (shown in the presentinstance as a centrifugal pump) raises the liquor from the tank 23 to a filter press. As liquor will normally be hot, the pump by gravity into the pump. The liquor rises from the pump through a pipe 25 and enters a filter press 26 erected beside the upper end of the trough 13. For the' purpose of keeping the filter press hot, it is lnclosed in a jacket 27 to which the gases of combustion are conveyed from the combustion and heating chamber (formed by the troughs 1 and 13 and their supporting masonry) the gases being conveyed by pipes'27a and 27", and the gases after passmg through the 'jacket 27 and around the filter press, escape by a stack 27. The pressure filter may be constructed in any desired manner, but as shown in the drawings, I have made use of a well-known type of filter comprising an outer casing 28, having a plurality of filter leaves 29 comprising cores made preferably of a plurality of layers of woven Wire and covered preferably with woven duck or canvas cloth. Each of the cores is connected to an airinlet pipe and to a liquid discharging pipe. In the illustrated press, the filter leaves are mounted onaframe that is ported on a track so that the leaves may be drawn out of the casing in dischargin In Fig'. 1a' the leaves are shown with awn from the casing 28 in position for: discharging the cakes'. In Fig. 4 they. are shown-1n the casing in position for the formation of the cake. The cake which accumulates upon thefilter leaves is discharged from the leaves 29 in any suitable manner and may after removal from the leaves not. be submitted to any further treatment in the apparatus, but

is discharged, for instance, by 'a spout (shown 1n dotted lines in Fig. 4) into a car to be taken away. i

.In the operation of my invention as carried out 1n the apparatus already described:

' lhe burner 10 being lighted and maintaining the materials at substantially the boil'- ing polnt of water, a supply from the wash `water and mother liquor tanks being furnished through their respective. pipes, and the ore feeding machine being supplied with callche, the process will proceed as follows: The mechanical arrangement of the ore feed- 1ng parts is such as to prevent the escape of steam from the trough 1.' The escape' of steam 1s, furthermore, prevented, owing to the' fact that when the steam comes into contact with the enterin body of caliche, the temperature of the ca iche will result in condensing the steam with which it has come mto contact. It is advantageous to prevent the escape of steam in order to maintain, as much of the same'body of dissolving liquor as possible continuously in the circulating system of the apparatus and also to prevent the escape of heat. Furthermore, the contact of the steam with the body of caliche being fed into the apparatus, will tend to pre-heat the caliche. From this point the caliche will be conveyed along the troughl 1,

.by the conveyer 2, toward the other end 2, its end edge (as shown in Fig. 5) constitutes a Wiper which passes down past the top edge of the lip 20, tending to wipe down and away from the top'of this lip, any sand or coarse slime which might otherwise overiow with the liquid. In this way, the percentage of slime which overfiows with the liquid discharged, is reduced. The burner 10, providing a current of heated air and products of combustion within the combustion and heating chamber beneath the troughs 1 and 13 will provide the desired maintained at approximately the center line of the screw. It is still necessary to remove the iners'particles of solids, whichare present-.in the -form of a slime in the liquid and this is accomplished by passing the liquid subsequently through the pressure\ filter 26. The liquid which flows into the reservoir 23 beneath the tanks 1 and 13 is withdrawn therefrom by the pressure pump 24:, from ywhich it is conveyed under a pressure of preferably 40 to 80 lbs. through the pipe 25 from the pressure filter. The temperature of the liquid in the ilter 26 should be'substantially the same as its temperature when leaving the trough 1. T-he liquid having been conveyed into the pressure filter 26, the pressure from the pump 24 causes the liquid to pass inwardly through the leaves of the filter, depositing upon the outside of the same, the remaining slime car-V ried by the liquid, which gradually accumulates upon the leaves of the filter to form a cake. When the cake has acquired its maximum thickness, as predetermined, the filter chamber is disconnected from the pump sup ply and the solution or pulp in the filter chamber about the cake is allowed to run back into the solution reservoir. To prevent the cake falling from the leaves when this .solution is removed compressed air, with a pressure approximatelyequal to that used in the filter when building the cake, is admitted from pipe 30 to displace the solution. After the removal of this solution the filter is filled with clear wash water, also under pressure, which is slowly forced through the filter cake, discharging from the inside of the leaves for a predetermined period. This liquid discharge contains in solution the salt recovered from the washing of the cake. The water is then shut ofi", the excess is drained from the filter, the lter is opened,

. the leaf rack is run out as shown in Fig. 1,

and the cake is discharged from the leaves by admitting a little water or steam or air to the inside of the leaves, which flushes or blows the cake oil". This 'cake is then thrown away, the lter is closed and operated through another similar cycle. The action of the pressure pump, together with the pressure filter, is such as to not decrease the temperature of the liquid, but rather to increase the same. This is advantageous, inasmuch as a decrease in temperature of the liquid might result in the deposition of some of the nitrate from-the liquid in ythe filter.

The solids passing upwardly through the trough 13 are subjected to the action of a current o f` wash water passing into the trough 13 from-the pipes 18 and 17'. The

current of lwash water is also by this means, Y

heated on its coming into contact with the heated ore, which has been discharged from the trough '1. The solids are then conducted upwardly along the trough 13 by means of `the conveyer 14, the soli s being' gradually d rai'nedI as they pass upwardly and the vliquid therefrom flowing downwardly and Joining the main body of liquid within the trough 1. Thesolids which have thus been \washed and drained are nally conveyed to the upper end of the' inclined trough 13, and

are discharged through the outlet grid opening 16. The ltered liquid whichpasses outwardly through the discharge pipe of conveyed to any .suitthe pressure filter is able apparatus to permit the liquid to cool vso as to allow the nitrate and other dissolved compounds to be deposited therefrom and the. mother liquor obtained after thev deposition of the solids is conducted to the liquid supply tank 9', from which it is conveyed into the' apparatus in the manner already described. There .are many advantages which occur 1n the operation of my invention. By preventing the escape of steam, there is a great saving, owinh to the fact that the escape of heat is prevented and owing to the fact that thesame amountV of water is continuously circulated in the apparatus, as far 'as possible. lt will be seen that the apparatus operates continuously and automatically,

thus producing a saving in labor and avoiding losses -due to repeated` handling. By means of my invention, the recovery of nitrate from caliche can be economically carried out in a very rapid manner Aby the operation upon the finely divided ore.. In previous processes, it has been found necessaryto treat the ore in the form of lumps of considerable size, in order to prevent the formation of slime in the liquid which could not be adequately removed. If. in previous apparatus, the caliche were treated in a comminuted form, there wouldbe a large amount of :slime carried away with ,the liquid and if the nitrate were to be allowed to deposit under such circumstances, a large amount of slime would be deposited with the nitrate in such a manner that the nitrate and slime could not thereafter be readily separated. The use of large lumps of ore caused a considerable amount'of waste and an additionalamount of labor was necessary in obtaining and sorting the lump ore. ln mv apparatus, however, the caliche in comminuted form may be operated upon, owing to the fact that the slime present therein is e'ectively and rapidly removed bv means of the pressure filters. As previously pointed out, the use of pressure filters prevents the deposition of the dissolved. solids during me.

thermore, in my apparatus, thc ore `and liquid are intimately mixed owing .to the plowing actin of the conveyors and'owing to the reverse and the liquid. The arrangementpf the `conveyer with the staggered openings-1s' such also asfto prevent the uninterrupted is brought are retained in the trough in Without dissolving the liow of the liquid Iofthe ore. Again,

soluble constituents l'there is a direct and eiiicient heating of the materials during solution, which heating about at the point Where the greatest dissolving' action is taking -place. There is also a very Aeiiioieiit washing of the exhausted ores notI only of the cake inthe filters but also of the remainder of the exhausted solids, which are .discharged into the inclined Wash and drain trough from the main horizontal'trough in which mostof the dissolving action takes place, inasmuch as-there is not only Washing in the filters themselves,- but there may also be a further Washing thereafter, both of the solids Washed in the filters and also ofthe remainder of the exhausted solids which which the dissolving action takes place. A further advantage is the fact that the 4vva'ter drained from the exhausted solids, is conveyed back into the mother liquid. 'Ihe pre-heating of I both thJ mother liquor and the calichev is istobe also a great advantage, especially in view of the fact that much of'this pre-heating is effected directly in connection with the apparatus used for dissolving the soluble constituents.r The treatment may be readily regulatedby adjusting the amounts ofv ore or dissolving liquor `feeds and the speeds of the conveying screws. It will also be seen that the various parts of the apparatus are readily accessible.

While I have described mv invention in detail, ,I Wish it to be understood that many changes may be made therein Without departing from the spirit of my invention.- It particularly understood that any other type of feeding means for the caliche and for the liquids may be used, if Afound desirable. Furthermore, any other type of desired apparatus for draining or removing the remaining liquor from the exhaustedore and for discharging' the exhausted ore,- may be used if desired', Within the scope of m foiind desirable, may be used for this purpose.- 'Agaim it is to 'be understood, that the filters which are used, may be substi tuted by any-other type of filter by which the results contemplated inmy invention may be obtained andthat said filters may be located at any desired place and that the ,cake from the filters may be discharged in any suitable manner, through any suitable outlet. Finally, it is of course to be lltration. Furdirections of How of the ore invention, and any separate mechanismunderstood, .that any other suitable type `of l heating means may be used that-is found to be desirable. i

1. In combination', a container, means for feeding. solid and liquid thereto without the escape of vapors from the container, and

" means for removing' solid and liquid therefrom withoutthe escape of vapors from the container.

2. In combination, a container, means for feeding solid and liquid thereto without the escape of vapors from the container, comprising a solid feedingmechanism sealed by the solid being fed, and means for removing solid and liquid therefrom without the escape of vapors from the container.

3. In combination, a container', means for feeding solid and'liquid theretowithout the escape of vapors from the container, and means forremoving solid and liquid therefrom without the escape of vapors from the container, comprising a liquid-sealed outlet through which the solid is removed.

4. I n combination, a container adapted t0 c ontain a solid, and means for feeding a liquid through the same, and arresting the flow therein from time to time.

. 5. In combinatioma container adapted to contain a solid, and means for feeding a liquid through the same and arresting the iovv therein from time to time, comprising ascrevv conveyer having staggered openings in-its blade.

6. In combination, a container, means for feeding solid and liquid thereto without the escape of vapors therefrom. and means for adjusting the relative 'quantities of solid and li uid so fed.

continuously feeding solid and liquid thereto,v and means for continuously removing solid and liquid therefrom 'without the escape of vapors from the container.

l0: In combination, a container, means for continuously feeding solid and liquid thereto, and .means for continuously removing solid and liquid therefrom'at' opposite ends of the'container, without the escape of vapors from the container.

11. In combination, a container for liquid and solidy having an outlet opening', an overflow-lip located at said opening and a Wiper' 'for the outlet opening.

- liquid near the other Laaacee 12. In combination, a container for liquid and solid having an outlet opening, an over fiow lip located at said opening and a Wiper for the outlet opening, comprising a screw conveyer having a spiral blade.

13. In combination, a container, means for conveying solid therein, means for supplying a body of solvent thereto without the escape of vapors therefrom, means for conducting the solid out of the container, on an incline, and means for supplying a Washing solvent on said incline.

14. In combination, an elongated receptacle, means for feeding salt bearing ore into the receptacle near one for feeding liquid near the other end thereof and means for Vconveying the ore from the inlet end to the other end Without the escape of vapors therefrom.

15. In combination, an elongated receptacle, means for continuously feeding salt bearing ore into the receptacle near one end thereof, means for continuously feeding a liquid near the other end thereof and means for continuously conveying the ore from the inlet end to the other end Without the escape of vapors therefrom.

16. In combination, an elongated receptacle, means for feeding salt bearing ore into the receptacle near one end thereof, means for feeding liquid near the other end thereof, means for conveying the ore from the inlet end to the other end vapors therefrom, and an elongated draining receptacle to receive the solid material discharged from the first mentioned receptacle.

17. In combination, an elongated receptacle, means for continuously feeding salt bearing ore into the receptacle near one end thereof, means for continuously feeding a end thereof, means for continuously conveying the ore from the inlet end to the other end Without the escape of vapors therefrom, and an elongated draining receptacle to receive the solid material discharged from the first mentioned receptacle.

18. In combination, an elongated receptacle, means for feeding salt bearing ore into the receptacle near one end thereof, means for feeding liquid near the other end thereof, means for conveying the ore from the inlet end to the other end Without the escape of vapors therefrom, an elongated draining receptacle to receive the solid material discharged from the first mentioned receptacle,

end thereof, means v Without the escape ofand means for supplying a Washing liquid to the solid.

19. In combination, an elongated receptacle, means for continuously feeding salt bearing ore into the receptacle near one end thereof, means for continuously conveying the ore from the inlet end to the other end Without the escape of vapors therefrom, an elongated draining receptacle to receive Athe solid material discharged from the first mentioned receptacle, and means for supplying a Washing liquid to the solid.

20. In combination, an elongated receptacle, means for feeding salt bearing ore into the receptacle near one end thereof, means for feeding liquid near the other end thereof, means for conveying the ore from the inletv end to the other end Without the escape of vapors therefrom, an elongated draining receptacle to receive the solid material discharged from the first mentioned receptacle, and means for supplying a Washing liquid to the solid in the draining receptacle.

21. In combination, an elongated receptacle, means for continuously feeding salt bearing ore into the receptacle near one end thereof, means for continuously feeding a liquid near the other end thereof, means for continuously conveying the ore from the inlet end to the other end Without the escape of vapors therefrom, an elongated draining receptacle to receive the solid material discharged from the first mentioned receptacle, and means for supplying a washing liquid to the solid in the draining receptacle.

In combination, an elongated receptacle, having a 'heating means, means for feeding salt bearing ore into the receptacle near one end thereof, means for feeding a liquid near the other end thereof and means for conveying the ore from the inlet end 'to the other en d Without the escape of vapors therefrom.

23. In combination, tacle having means for salt at least artially soluble therein, a heaterfor saidp receptacle, a pressure filter for receiving the resulting solution, and means for leading the exhaust from said heater to the pressure lter.

In testimony that I claim the foregoing I have hereunto set my hand.

PHILIP G. DARIJING.

an. elongated recepmlXmg a liquid and [Witnesses:

HAMLLTON BRADSHAW, CHARLES E. Anno 

